Cigarette smoking is the number one preventable cause of morbidity and mortality in this nation (CDC, 2002; Mokdad, 2004) and despite large public health efforts; nearly a quarter of the U.S. population still smokes (CDC, 2002). In addition to targeting the adult population in general, particular interest has been placed on aggressively targeting those at greater medical risks for smoking related diseases (Fiore et al., 2000). One such high risk groups are childhood cancer survivors. There are nearly a million adult survivors of childhood cancer (Weiner et al., 2003). Currently, the cure rate for pediatric cancers exceeds 75% and the number of childhood cancer survivors is dramatically increasing (Bleyer, 1990). Behavioral lifestyle risk factors for cancer (e.g., smoking, obesity) are common in these survivors, placing them at risk for secondary cancers. While the exact prevalence of smoking is unknown in cancer survivors, estimates place the prevalence of smoking nearly as high as in the normal, adult population (Emmons et al., 2003). As such, identifying efficacious smoking cessation (and prevention) programs is a high priority. One of the major logistical problems with smoking cessation efforts in childhood cancer survivors is that of geographic diversity while cancer survivorship is common (and growing), the numbers of cancer survivors, for example, in any given medical practice, is likely to be very low. Proactive Tobacco Quit Lines (QL) show promise in terms of efficacy, are being widely disseminated, and overcome the potential problems associated with participants being located in diverse areas. However, no study has evaluated the efficacy of a targeted tobacco quit line for cancer survivors. Given that QL interventions can address the issues of mobility and remote access present in childhood cancer survivors, validating the efficacy of a QL in a cancer survivor population is a high priority. Thus, the Specific Aims of the current study are as follows: (1) To recruit nationally a cohort of approximately 950 smokers who are childhood cancer survivors; (2) To determine the long-term (one year) efficacy of the intervention condition for participants randomly assigned to the Proactive versus a Reactive QL. The St. Jude Cancer Survivors Tobacco Quit Line (SJCSTQL) is proposed to be a quit line targeted to cancer survivors. If efficacy is established with the QL, St. Jude is committed to provide the resources to disseminate the QL as part of its outreach efforts. The study will investigate whether a stop smoking program delivered over the phone and through the mail will enhance smoking cessation in a very high risk medical population; namely, adult survivors of childhood cancer. If successful, the program will be disseminated nation wide and has the potential of reducing cancer in this at risk population.